China has started the countdown to launch a space station module, the Tiangong-1, that is the first step in establishing a permanent manned presence in orbit above the Earth.

A Long March 2F rockey carrying China's Tiangong-1 space station module is awaiting lift-off on Thursday. Photograph: AFP/Getty

A Long March II 2F rocket is scheduled to take off soon after 1.16pm GMT on Thursday from Jiuquan in Gansu province, carrying the laboratory to an altitude of 220 miles (350km) where it will circle the planet unmanned while its systems are tested.

A crew capsule, Shenzhou 8, is to be launched unmanned in November and carry out docking tests with the Tiangong, which means "heavenly palace".

Manned missions by Chinese astronauts, known as yuhangyuans, are to begin in 2012, according to Chinese state media.

A backup, Tiangong 2, has been built in case Thursday's launch goes wrong.

China's eventual aim is to build a 60-tonne space station within 10 years – it will be about a sixth the mass of the International Space Station.

The Tiangong is believed by international analysts to include docking technology based on Russian designs.

Yang Liwei in 2003 became the first man put in orbit by China's space programme, circling the Earth 14 times during 21 hours in orbit. Five others have followed him in crews of up to three at a time.

The diving bell-shaped Shenzou is similar to the Russian Soyuz but as a whole the Shenzou is larger and has greater flying capabilities in orbit.